Model output discussion pm 13/01/2016

[Polar Maritime]

A bone chilling -16c showing on the NetWx-MR model for Saturday night.

Edited January 15, 2016 by Polar Maritime

[Lukesluckybunch]

8 minutes ago, Weathervane said:

I was fascinated by that UKMO day 6 chart last night. It could have led almost anywhere. Worst, it could have been the sink hole down which our cold weather dreams were to disappear. Now I can see rabbits coming out of a hat. You can analyse this to bits, but whatever the outcome, the Met and their models have been remarkable.

 

So are you saying this is a positive thing,is good for cold?

[Timmytour]

29 minutes ago, emotional rollercoaster said:

It's my birthday today my name is Chris I'm 41 and I've never seen a hurricane track straight north ever.

ive got a feeling cold will stay around possibly milder in our location sunny Costa south coast.

but great news I'd of thought although I'm no expert but warming event in the strat perhaps because of the Atlantic tropical storms up tick surely.

Emotional....... Apologies, this may be actually me getting the wrong end of the stick.....but you do realise that bluearmy was replying to someone called Chris about the path of ex Hurricane Alex....and the ex tropical storm itself is not called Chris?  :-)

[wiltshire weather]

An interesting recent comment from Ian F over in the SW regional thread,

quote:

Yes, some troubling-looking selections of output this morning for early next week, more especially for N and E of W Country. But exceptionally low confidence on what will unfold. Interestingly, latest UKMO overnight prognosis through Feb builds Atlantic block with us on colder eastern side/troughing... we may have the experience of current period to unravel yet again further down the line

[nick sussex]

I will only be commenting on output upto the current reliable timeframe which is currently T24hrs! lol

Well you really couldn't make it up given this mornings model swings. I have little faith in any of the outputs as these wild swings mean any prediction made now will probably implode by this afternoon.

However theres one thing they do actually agree on and that's the deeper low exiting Newfoundland which looks like phasing favourably with the upstream troughing.

In terms of the GFS I feel rather vindicated after "low ejection gate" last night, this now separates shortwave energy/weakish low pressure from the upstream troughing.

This is really what you want to see because this will support high pressure further north, the UKMO finally gets there at T144hrs. The ECM is a bit less favourable in terms of that.

As to what actually verifies really more runs are needed, yes its an awful cliché but that's really the state of play today.

Edited January 15, 2016 by nick sussex

[Weather Boy]

2 minutes ago, wiltshire weather said:

An interesting recent comment from Ian F over in the SW regional thread,

quote:

Yes, some troubling-looking selections of output this morning for early next week, more especially for N and E of W Country. But exceptionally low confidence on what will unfold. Interestingly, latest UKMO overnight prognosis through Feb builds Atlantic block with us on colder eastern side/troughing... we may have the experience of current period to unravel yet again further down the line

Translation: "we don't have a clue!"

And with the current NWP output, who can blame them!

[Chris1986]

Another update from the hurricane center. I don't think any of the models Could possibly have a handle on this.

[Chris1986]

If that comes off it would be the first post tropical cyclone to hit greenland in history.

[BLAST FROM THE PAST]

UKMO, GEM excellent runs.

UKMO showing Atlantic mild trying to win

It has a go but isn't winning

 

Is this the type of scenario Fergie was tweeting about re cyclonic activity running to south of UK.  I am finding this very interesting especially as it is playing havoc with forecaster's thoughts/outlooks.  I think we are in for a cold to slightly less cold to very cold ride ahead.  Very encouraging indeed for the rest of winter.

 

BFTP

 

Edited January 15, 2016 by BLAST FROM THE PAST

[radiohead]

1 hour ago, Chris1986 said:

Gfs has the hurricane modelled incorrectly in strength and path It would appear. 

 

National Hurricane Center puts Alex at 986mb. The 0Z GFS has Alex 987mb. It's pretty much bang on.

As for the track, the cone of uncertainty is very narrow which shows there is a high degree in confidence in the expected track. GFS ensembles show complete agreement in the track up until the point it phases with another low after it becomes extratropical.

 

 

[Gibby]

HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS ISSUED AT 09:00 ON FRIDAY JAN 15TH 2016

THE CURRENT GENERAL SITUATION   A cold NW flow will ease away East with a High pressure cell moving across the UK from the west over the weekend.

http://www.wetterzentrale.de/pics/Rtavn001.gif

 CURRENT SNOW FORECAST AND FREEZING LEVEL OVER THE UK The freezing level across the British Isles will lie around 500m or 2000ft for much of the UK with any precipotation falling as snow over hills above 200m

http://www.snow-forecast.com/maps/dynamic/uk

http://www.natice.noaa.gov/pub/ims/ims_gif/DATA/cursnow.gif

MODELS-2 WEEK HEADLINE  Very Cold and frosty with the chance of snow for a time next week then probably becoming less cold for all with some rain in the North.

THE GFS JET STREAM FORECAST  The main theme of the Jet Stream today shows the Jet Stream running South across the UK over the coming days having crossed the Atlantic on an Easterly track around 50deg North. The flow then largely disrupts next week as far as the UK is concerned as it becomes much lighter and less well defined across Europe for a time before it realigns West to East across the Atlantic across Northernmost Britain.

http://www.netweather.tv/index.cgi?action=jetstream

GFS OPERATIONAL The GFS Operational Run today shows cold conditions lasting across the UK into next week as the ridge at the weekend gives way to disrupting Low pressure across the UK with an awqward mix of rain and snow moving up across the UK from the SW early next week. Thereafter High pressure re-establishes to the East for a while with chilly and drier conditions for many before the Atlantic returns later with SW winds and rain at times especially across the North and West later with temperatures closer to average or a little above at times. 

GFS CONTROL RUN The theme of the Control Run is very similar in theme with the milder air not reaching many parts of the UK until later next week following a mix of rain and snow in raw conditions early on in the week. The milder SW winds then take hold but with High pressure never far away from the South a lot of dry weather is expected with rain mostly restricted to the North and West for a lot of the time.

http://www.wetterzentrale.de/pics/Rtavn1441.gif

http://www.wetterzentrale.de/pics/Rtavn3841.gif

http://www.meteociel.fr/modeles/gefs_cartes.php?code=0&ech=144&mode=0&carte=0

http://www.meteociel.fr/modeles/gefs_cartes.php?code=0&ech=384&mode=0&carte=0

UKMO The UKMO model today is once more wanting to prevent much encroachment of milder Atlantic air into the UK next week with Low pressure and troughs moving into the UK bringing an impossible to forecast mix of rain and snow across the UK at times. My own thoughts reflect on snow mostly for northern parts early in the week and perhaps the South later as the cold extends back South with a Low to the South and SW by then and an Easterly flow across the South

http://www.wetterzentrale.de/pics/Rukm1441.gif

THE FAX CHARTS The Fax Charts today show the difficult battle between cold air across the UK and Europe with milder Atlantic air moving in from the West and SW. Progress of troughs is shown to be slow and arduous with a real risk of snow for some early next week.

http://www.weathercharts.org/ukmomslp.htm#t120

GEM GEM this morning shows cold and anticyclonic conditions this weekend as High pressure is maintained close to the UK. Then through next week disrupting Low pressure near the UK brings a messy mix of rain and snow to almost anywhere for a time before it becomes drier and rather cold for a time as High pressure re-establishes to the NE. Then this is shown to collapse later with milder SW winds sending warmer air slowly NE across the UK reaching the NW first and the SE last.

NAVGEM NAVGEM looks fine and settled over the weekend this morning but cold and very frosty. After the weekend Low pressure troughs move slowly into the UK from the SW with a messy mix of rain, sleet and snow for several days as Low pressure disrupts it's way SE over Southern Britain. Later next week High pressure to the East eases away SE allowing milder Atlantic SW'lies to establish late next week away from the SE.

ECM ECM today shows another variation on the same theme as the rest of the output with disrupting troughs early in the week delaying the progress of milder air into the UK with the risk of rain and snow in places early in the week. On this run a wet spell develops late next week with Low pressure zipping East across Scotland before strong High pressure ridges up from the South to end the period with a lot of dry and benign weather in average temperatures and a Westerly breeze.

http://www.wetterzentrale.de/pics/Recm2401.gif

ECM 10 DAY MEAN The 10 day mean chart shows a similar theme as it has for the last few days and I'm not entirely sure what to read from it today as I feel it is looks too simplistic on what could be a complex set of members each showing very different solutions.

http://www.wetterzentrale.de/pics/Reem2401.gif

NOTABLE TRENDS & CHANGES FROM PREVIOUS RUNS The models continue to show different options towards how long the cold weather across the UK lasts but the end theme for milder weather for all by the end of next week is still maintained this morning.

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The verification Statistics of GFS, UKMO and ECM show at 24 hours ECM ahead at 99.6 pts with UKMO  and GFS at 99.4 pts respectively.  At 3 days ECM is leading with 97.6 pts to UKMO's 96.8 pts while GFS lags behind at 96.4 pts. At 5 days ECM leads with 90.1 pts to UKMO at 88.2 pts then GFS at 87.1 pts. Then at 8 Days ECM still leads at 66.2 pts over GFS's 63.2 pts. Finally at Day 10 ECM is ahead of GFS at 49.0 pts to 45.9 pts respectively. 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day1_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day3_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day5_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day8_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day10_PMSL_MSL_G2NHX.png

MY THOUGHTS   It does appear this morning as the pack of models have come dragging and screaming towards the UKMO solution that it has shown for days now although I feel the end realisation will change much more in the coming days. What we have in the short term is a strong High pressure ridge moving across the UK at the weekend although a spanner in the works is a trough up to the NW which slipping down across Northern areas at the weekend could take away the sunny skies and sharpest frosts by Sunday with some rain and snow in the North and NW. The main event though still appears to be the risk of snow and rain from the SW early next week as an ex Hurricane Alex moves North then NW across the West Atlantic. This is likely to strengthen the resolve of High pressure over or to the North of the UK and helps block the otherwise easy progress East of the associated milder air approaching the UK from the SW early next week. This means a very messy mix of rain, sleet or indeed snow could be a real risk for many next week but where and how much if any is yet to be determined. It then looks this morning that a short resurgence of High pressure from the East later next week could delay the second push of milder air too though this from most output looks much more successful in swamping all of the UK next weekend and beyond with the status quo of rain at times in the North and drier weather in the South with average temperatures at least for all by then. The models are all over the place currently and until the fragments of ex hurricane Alex have left the scene early next week we will probably continue to see further swings in outputs run to run. As a result confidence in my report comes with lower confidence than usual and things could continue to surprise us within the models in the coming days before the real solution is realised. More tomorrow.  

Next Update Saturday January 16th 2016 from 09:00 

[TEITS]

I was going to post this morning about my concern with regards to the consistent awful medium range trend of high pressure to our S and a very mild W/SW,ly. I then however had a look at the GEFS ensembles and noticed the incredible scatter very early in the run.

Based on all output I would say we have a 60% chance of it turning milder, 30% remaining cold and settled, 10% epic cold spell similiar to 78/79. Shall update these percentages later.

[Timmytour]

11 minutes ago, Chris1986 said:

Another update from the hurricane center. I don't think any of the models Could possibly have a handle on this.

Looks to me like a marked divergence with GFS at T33 onwards...which I guess makes that FI for the time being!

[nick sussex]

Looking at the ECM postage stamps a real mix of solutions the majority want to take more energy over the top:

http://old.ecmwf.int/samples/d/inspect/teasers/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!120!pop!od!enfo!enplot!2016011500!!/

I'd say around 11 of the ensembles take more energy se'wards, the operational and control agree with some energy going se'wards but we'd need to see a lot more.

Ensembles in this type of set up can be even more jumpy than the operational runs.

[Singularity]

Well at least there's one nice shorter-term run to look at here:

http://www.meteociel.fr/modeles/icone_cartes.php

I do like how the hourly intervals lets you see the process very clearly; the WAA heads NE with the cold air behind, this being a marked frontal boundary. At the same time low heights extend SE along the boundary to the UK and it becomes a question as to how well that can become focused into a separate system from the main trough.

This model seems to do that rather well, but I'm not sure of ICON's track record since it was upgraded from GME?

Notice the nose of lower heights into the western Channel right at the end - suggests to me the boundary is just off the SW as of 7 am Monday.

 

With ARPEGE however, it's a case of close but no cigar... or at least not a cigar as far south as we'd like it:

 

The squashed appearance of the next Atlantic trough is of some interest though. I'm starting to get a (for me nasty) feeling that the north might get pasted at times from the middle of next week while the south is drenched. If only that Azores-Euro ridge would calm down a bit... actually it is weakening during the final day of that run so who knows what might happen.

 

The global models aren't that far off at +96 to be fair, but they trash things by +120 as the lows heights gather themselves into a more rounded trough with the jet firing NE ahead of it. Under such a pattern, a combination of the active subtropical jet encouraged by the El Nino and the current Atlantic SST profile is likely to promote LP development west or southwest of the Azores... hence those majorly pumped up ridges across Europe and the UK that keep cropping up longer-term.

Hopefully we can at least have high pressure over the UK rather than just to the south. In either case the odds are such a feature is what heads north when the polar field changes again late month into Feb in response to trop/strat forcing. How soon that happens is unlikely to be something easily discernible from the model output at the moment; there's too much risk that they're mishandling the trop. response to the mid-term spike in strat. vortex intensity ahead of the anticipated weakening thereafter.

[Chris1986]

21 minutes ago, Timmytour said:

Looks to me like a marked divergence with GFS at T33 onwards...which I guess makes that FI for the time being!

Well I'm not sure but I'm guessing they are running these models full time from the livestream data what with being the national hurricane center tasked with preventing loss of life In massive numbers I think they have the budget  

[Weather Observer]

40 minutes ago, Lukesluckybunch said:

So are you saying this is a positive thing,is good for cold?

Yes I do. But my opinion is only based on watching the meto over the years slog it out with the other models in these knife edge situations in winter. The longer we keep the cold in the better the prospects for snow.

[Timmytour]

5 minutes ago, Chris1986 said:

Well I'm not sure but I'm guessing they are running these models full time from the livestream data what with being the national hurricane center tasked with preventing loss of life In massive numbers I think they have the budget

I wouldn't be backing GFS in the scenario

[mb018538]

How amazing to have a hurricane in January! I think it's only the 4th time on record it's happened? No wonder none of the models can handle this. BBC think that Alex will be absorbed into the general pattern and give the jet that shot of energy it needs to break through and turn things unsettled....though this is of course still very uncertain. Absolutely fascinating, and such a welcome break from Decembers tedious model watching of T+infinity showing wind and rain ad nauseum !

[No Balls Like Snow Balls]

The SAGA continues

 

 

 

[SMU]

Just adding to singularity post from earlier

this feature which the GFS hopefully over develops is the reason for the positive tilt

it needs to disapear sharpish ( for the south anyway ) 

make the image as clear as possible !!

s

[SMU]

06z Small changes at 36 creeping in- very hard to see unless your flicking between 2 runs

at 36 now as Alex gets absorbed into the main low the CAA under main low where out slider develops is angled more NW SE - the 00z had a similar angle but less acute...

that angle ( maybe 5 degrees) should help at 72 & 96

S

[That ECM]

Marginally better angle.

Edited January 15, 2016 by That ECM
SM beat me to it!!

[karlos1983]

7 minutes ago, Steve Murr said:

06z Small changes at 36 creeping in- very hard to see unless your flicking between 2 runs

at 36 now as Alex gets absorbed into the main low the CAA under main low where out slider develops is angled more NW SE - the 00z had a similar angle but less acute...

that angle ( maybe 5 degrees) should help at 72 & 96

S

and the high looks slightly further north, if you again flick between 00z and 06z, small differences could  = big change in the outcome

Edited January 15, 2016 by karlos1983

[TSNWK]

Wow! I have been about for 10 years and I cannot recall in all that time the models at 48 hours and less coming under the spotlight like this.. Really unprecedented.